Penning Ionization Electron Spectoscopy: Its Application to Surface Characterization of Organic Solids

Abstract

In Penning ionization electron spectroscopy, the kinetic energy of electrons ejected by collisions between targets T (gas or solid) and metastable rare gas atoms A* is analyzed. This electron spectroscopy is selectively sensitive to the outermost surface layer of solids, since metastable atoms do not penetrate into inner layers. Furthermore, it provides information on the local electron distribution of individual orbitals exposed outside the outermost surface layer. The application of these unique features of Penning spectroscopy to the surface characterization of organic solids, including Langmuir-Blodgett films, is discussed. Both a Penning spectroscopy technique and the process of Penning ionization of gas-phase molecules are briefly described.